On the role of boundary conditions in the simulation of large deformation rockfall barriers

In recent years, the advances in computational power have enabled the explicit simulation of each individual components of rockfall barriers. However, this approach remains thus far constrained to structures with a relatively low number of elements. For stochastic or sensitivity analyses, where computational efficiency is crucial, a multi-scale approach is generally preferred. Within this context, the Discrete Element Method (DEM) offers efficient modelling of interactions among a large number of bodies but sacrifices some representativeness, particularly in the way structural elements such as fence posts and selvedge cables are implemented as boundary conditions. In this study, a recently developed macroelement model for double-twisted mesh is used to simulate the response of a mesh panel loaded using a circular platter. The structural elements, i.e. fence posts, are modelled using a combination of fixity conditions applied to discrete elements and coupling with continuum elements. A parametric analysis is then conducted to identify the effect of the boundary conditions. This analysis aims to quantify how the underlying assumptions affect the failure state of the barrier in the scope of reliability analysis for the mitigation of natural hazards.